Asked by: Tanya Sebastian, by email
One idea is that in our evolutionary past we were surrounded by spiders that were dangerously venomous and this favoured our ancestors, who would run a mile when something scuttled along the skirting board. The problem with this theory is that arachnophobia is much more common in Europe than in Africa or South America. An alternative hypothesis is that spiders mistakenly became associated with disease in the Middle Ages – particularly with the Black Death. This led to a cultural aversion to spiders, which has been handed down through the generations ever since.